Sling psychrometer



June 11, 1963 w, J, MAYO 7 3,092,996

SLING PSYCHROMETER Filed Jan. 11, 1962 HI IIIIIHHIHHIIHHIIIHI IHHIHHIIIHIIHIIHHHHHIIIIIHHHIIIIIHIII I9 is 17 2| F N H65 INVENTOR.

WILLIAM J. MAYO A TTORNEY United States Patent 3,092,996 SLING PSYCHROMETER William J. Mayo, 6219 Loch Raven Road, Camp Springs, Md. Filed Jan. 11, 1962, Ser. No. 165,542 Claims. (Cl. 73-338.6)

This invention relates to psychrometers.

Sling psychrometers are commonly employed for accurately determining relative or absolute humidities in buildings or the like. Most frequently, sling'psychrometers embody a holder for a wet bulb and a dry bulb thermometer held in side-by-side relation, with the holder secured to a flexible member such as a cord or chain. The user of the instrument whirls the thermometer assembly in a circular path through the air while holding the flexible member in one hand. This arrangement has several disadvantages. In office buildings and the like where much furniture is present, there is quite a possibility that the thermometer assembly during whirling may strike some object such as a wall or a piece of furniture and become broken. relatively expensive and the likelihood of breakage in the above manner is obviously undesirable and uneconomical.

The conventional instruments are It has been proposed by the prior art to mount the wet bulb and dry bulb assembly on a rigid handle structure for whirling and with the two thermometers arranged in side-by-side relation and projecting radially from one side of the handle structure. While this arrangement may lessen somewhat the likelihood of breakage, it still is not satisfactory mainly because the whirling psychrometer is unbalanced with the entire mass of the thermometers and holder extending upon one side of the handle. During operation, the unbalanced rotor effect is somewhat diflicult to control with the hand and if the user of the instrument is standing near a wall or the like and is not extremely careful, the effect of centrifugal force may cause the instrument to strike the wall or some like obwith the carrying handle for rotation thereon in a novel,-

compact and simplified manner.

A further important object of the invention is to provide novel and simplified detent means for securing the wet and dry bulb thermometers releasably in radially extended or active positions relative to the handle and in folded or collapsed inactive positions parallel to the handle. 7

Another object is to provide a psychrometer of the vmentioned character wherein the two thermometers extend radially upon opposite sides of the handle during .use to provide a substantially balanced rotor, the two thermometers swinging into parallelism with the handle and close to the same on opposite sides thereof when in the inactive position, whereby the entire instrument can be readily stored in a small carrying case adapted to be placed in the pocket of a garment.

Still another object is to provide a psychrometer which may be manually rotated or driven by a small motor.

Other objects and advantages of the invention will be apparent during the course of the following description.

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In the accompanying drawings forming a part of this application and in which like numerals are employed to desgnate like parts throughout the same,

FIGURE 1 is a side elevation of a sling psychrometer according to the invention and showing the wet and dry bulb thermometers in a folded or inactive position with relation to the handle structure,

FIGURE 2 is an enlarged fragmentary central vertical section, partly exploded, through the psychrometer shown in FIGURE 1,

FIGURE 3 is an enlarged transverse vertical section taken on line "3-3 of FIGURE 2,

FIGURE 4 is a similar section taken on line 44 of FIGURE 2,

FIGURE 5 is a perspective view showing the sling psychrometer during use with the wet and dry bulb thermometers radially extended for manual rotation,

FIGURE 6 is a side elevation on a reduced scale of the psychrometer and a carrying case therefor,

FIGURE 7 is a partly diagrammatic side elevation of a motor operated psychrometer in accordance with a modification of the invention.

In the drawings, wherein for the purpose of illustration are shown preferred embodiments of the invention, attention is directed first to FIGURES 16 inclusive, wherein the numeral 110 designates a straight preferably cylindrical rigid handle of a size .to be conveniently held in one hand in the manner shown in FIGURE 5. Adjustably rigidly secured to the forward end of the handle 10 and extending axially forwardly thereof is a reduced diameter bolt or shaft 11 having screw-threaded engagement within a screw-threaded bore 12, formed axially in the handle @10, and locked in the selected adjusted position by a lock nut 13. Freely rotatably mounted upon the shaft 11 is a balanced rotor including a forward crosshead 14 provided in its opposite ends with radial screwthreaded openings 15, disposed in diametrically opposed relation. The ends of the crosshead 14 are spaced equidistantly radially from opposite sides of the shaft 111, as shown. The rotor further includes a reduced neck portion 16, and rearwardly thereof an enlarged preferably cylindrical knurled operating or turning portion 17 integral therewith and arranged immediately forwardly of the handle 10 in axial alignment therewith. The portion 17 is adapted to be engaged by the fingers of the hand, as shown in FIGURE 5, for turning the rotor relative to the handle while the instrument is being held in the hand. As shown in the drawings, the crosshead 14 is preferably hexagonal in cross section to facilitate gripping the same with a wrench or pliers. A

Pivot screws 18 engage within the screw-threaded openings 15 of the crosshead and extend radially of the crosshead with the heads 19 spaced radially beyond the ends of the crosshead. Rotatable upon the pivot screws 18 are sleeve elements 2t), urged inwardly toward the ends of the crosshead by spring washers 21, mounted upon the screws 18, between the heads 19 and the outer faces of the sleeve elements 20.

On the inner face of each sleeve element 20, FIGURE 4, is a radial rib 22 for selective engagement within either of a pair of radial grooves 23 formed in the adjacent outer face of the crosshead 14 and spaced apart circumferentially degrees, FIGURE 3. This arrangement forms -a resilient releasable detent for each sleeve element 20 so that the latter may be selectively positioned rotatably relative to the crosshead 14 at two stations 90 degrees apart, corresponding to the active and inactive positions of the thermometers to be described. The springs 21 constantly urge the inner faces of the sleeve elements 20 against the outer ends of the crosshead 14, and the ribs 22 which are preferably rounded slide freely over the end faces of the crosshead and may drop selectively into -is shifted axially from the end face of the crosshead, and

the adjacent spring washer 21 yields to permit this shift- Each sleeve or pivot element 29 has a short radial extension 24 integral therewith, and parallel to the bolt or shaft 11. Each extension 24 carries an enlarged cylindrical internally screw-threaded socket sleeve 25 integral therewith and having its axis spaced from and parallel to the axis of the handle and shaft 11. Within each socket sleeve 25 is engageable a screw-threaded clamp fitting 26 of conventional construction, for releasably securing to the particular socket sleeve the wet bulb thermometer 27 or the dry bulb thermometer 28. These thermometers 27 and 28 are conventional and well-known devices common to all sling psychromet-ers and need not therefore be described in detail herein. The socket sleeves 25 and fittings 26 lie close to opposite sides or" the cylindrical turning element 17, FIGURE 1, when the thermometers 27 and 28 are folded into parallel substantially coextensive relation with the handle 10 and in substantially coplanar relation therewith. When so folded, the

balanced rotor assembly to be turned by the fingers. The

detent means including rib 22 and groove means 23 is now active to maintain the thermometers releasably locked 'in the radially extended, positions extending from opposite sides of the crosshead and handle. The user by .spinnnig the knurled element 17 may rapidly revolve the thermometer assembly through the air to secure the desired thermometer readings necessary for the determination of relative humidity in a room or the like. The rotor structure embodying the thermometers 27 and 28 and the crosshead 14 is substantially balanced and there is no flexible connection embodying a chain or the like between the assembly and the hand of the user as is common in the prior art with the resultant likelihood of dam- ,ge or breakage of the instrument.

compact, efiicient in operation, and economical to manufacture, and standard or conventional thermometers may be employed.

FIGURE 7 shows a modified form of the invention, wherein the rotor structure embodying the thermometers may be power driven. In figure, a tubular handle 30 is employed containing a plurality of small storage batteries 31 for operating a miniature electric motor 32 housed within the leading end of the handle. A cross head 33 similar to the crosshead 14 is provided and carries the thermometers 27 and 28 in the identical manner shown and described in connection with the prior form of the invention. The crosshead 33 has a radial shaft extension 34 integral therewith and arranged coaxially with the armature shaft of the motor 32, and coupled thereto to be driven directly thereby in any conventional manner. The motor 32 and its controls are conventional andvvell-known and need not be described in detail herein. A suitable starting and stopping switch for the motor, not shown, may be provided upon the handle 30 at any convenient point.

In use, the thermometers are extended in the identical and spaced upon opposite sides of the handle and sleeve device, and resilient detent means interconnecting said 4 manner shown and described in connection with FIG- URE 5 and the motor 32 is started to impart rotation to the rotor assembly which includes the crosshead 33 and the thermometers. All other parts are identical with the corresponding parts shown and described in the first form of the invention.

It is to be understood that the forms of the invention herein shown and described are to be taken as preferred embodiments of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of the invention or scope of the subjoined claims.

' Having thus described my invention, I claim:

1. A psychromcter comprising a supporting handle, a manually operable rotor journaled upon the supporting handle, a wet bulb thermometer and a dry bulb therinometer pivotally secured to said rotor upon an axis transversely of the handle and rotor and movable with the rotor, said thermometers swingable upon the rotor to active positions radially of the rotor and handle in diame'trically opposed relation and also swingable to inactive positionson opposite sides of the handle and rotor in substantially coplanar parallel relation with the handle, and detent means releasably locking said thermometers in said active and inactive positions.

2. A psychromcter comprising a supporting handle, a rotor structure journaled upon said handle in coaxial relation thereto and including a crosshead, a wet bulb and a dry bulb thermometer on opposite sides of said handle, means carrying said thermometers and pivotally secured to opposite ends of the crosshead and swingable relative thereto to radial positions wherein said thermometers extend in opposite directions from the crosshead and transversely thereof and transversely of the handle, said thermometers also swingable to folded positions on opposite sides of the handle in substantially parallel coplanar relation thereto, and releasable detent means for securing said thermometers in said radial and parallel coplanar positions.

3. A psychrometer comprising a supporting handle, a

sleeve device coaxial with the handle forwardly thereof and journaled thereon for rotation and having a crosshead, pivot elements secured to opposite ends of the crosshead transversely of the handle and sleeve device, thermometer holding socket elements pivotally mounted upon the pivot elements and extending at right angles thereto socket elements and crosshead for releasably securing the socket elements in circumferentially spaced radial positions relative to the crosshead.

4. The invention as defined by claim 3, and an enlargement on the sleeve device to facilitate turning-the same with the fingers. I

5. The invention as defined by claim 3, and wherein said detent means comprises intcrengaging rib and groove means on the socket elements and crosshead, and resilient elements engaging the socket elements and urging them toward the crosshead and tending to maintain engagement of said rib and groove means.

6. A psychromcter comprising a supporting handle, a. crosshead journaled for rotation upon one end of the handle, a wet bulb and a dry bulb thermometer pivoted to opposite ends of the crosshead and extending transversely thereof and swingable relative thereto to dia- 65 metrically opposed radial positions transversely of the handle on opposite sides thereof, said thermometers also swingable to parallel substantially coplanar positions relative to the handle on opposite sides thereof, and resilient detent means releasably securing said thermometers in said opposed radial and parallel coplanar positions.

7. The invention as defined by claim 6, and a finger engaging element connected with the crosshead between said thermometers and coaxial with the handle and 0perable for turning the crosshead manually.

8. The invention as defined by claim 6, and motor means mounted upon the handle and connected with the crosshead to turn the same.

9. The invention as defined by claim 8, and wherein the motor means comprises a battery and a miniature motor mounted within the handle, said handle being at least in part tubular.

10. A psychrometer comprising a handle of a size to be held in one hand, a shaft extension on the forward end of the handle coaxial therewith, a sleeve device journaled upon the shaft extension and having an enlargement to be engaged by the fingers for turning, a crosshead secured to the sleeve device and extending equidistantly radially on opposite sides thereof and beyond opposite sides of the handle, sleeve elements pivotally secured to opposite ends of the crosshead, releasable detent means connected with the sleeve elements to secure them in a plurality of radially adjusted positions relative to the crosshead, radial socket members carried by the sleeve elements and adapted to extend parallel to the handle in coplanar relation thereto or transversely of the handle beyond opposite sides thereof, and wet and dry bulb thermometers detachably engageable with said socket 10 members.

No references cited. 

10. A PSYCHROMETER COMPRISING A HANDLE OF A SIZE TO BE HELD IN ONE HAND, A SHAFT EXTENSION ON THE FORWARD END OF THE HANDLE COAXIAL THEREWITH, A SLEEVE DEVICE JOURNALED UPON THE SHAFT EXTENSION AND HAVING AN ENLARGEMENT TO BE ENGAGED BY THE FINGERS FOR TURNING, A CROSSHEAD SECURED TO THE SLEEVE DEVICE AND EDTENDING EQUIDISTANTLY RADIALLY ON OPPOSITE SIDES THEREOF AND BEYOND OPPOSITE SIDES OF THE HANDLE, SLEEVE ELEMENTS PIVOTALLY SECURED TO OPPOSITE ENDS OF THE CROSSHEAD, RELEASABLE DETENT MEANS CONNECTED WITH THE SLEEVE ELEMENTS TO SECURE THEM IN A PLURALITY OF RADIALLY ADJUSTED POSITONS RELATIVE TO THE CROSSHEAD, RADIAL SOCKET MEMBERS CARRIED BY THE SLEEVE ELEMENTS AND ADAPTED TO EXTEND PARALLEL TO THE HANDLE IN COPLANAR RELATION THERETO OR TRANSVERSELY OF THE HANDLE BEYOND OPPOSITE SIDES THEREOF, AND WET AND DRY BULB THERMOMETERS DETACHABLY ENGAGEABLE WITH SAID SOCKET MEMBERS. 